mplayer with all the win32 codecs will play .mp4, .mov
VLC will too as I recall.
Totem, Xine.. all of them should play .mp4, .mov with the all codecs package.
I think that I have heard buntu users say that there is a community repository that you need to include that has those. Do a search on LQ, I've seen this talked about over the years.
http://www.mplayerhq.hu/design7/dload.html
http://ubuntuforums.org/showthread.php?t=1433198
You might want to search/ask in the buntu forum.
http://www.linuxquestions.org/questions/ubuntu-63/